Ex offers me to friend

This story is from when I was married. A few things you need to know about my marriage and the ppl in this story. My ex and I had a good sexlife. But like most ppl never enough and also I love licking pussy but she didn’t like receiving it., apparently she never had. We were friends with a couple, Gary and Kat, and spent a lot of time with them often drinking a lot and ending with us guys watching our wives making out. We were cool with it as we knew when we got home there would be a great session had.
With Gary and Kat there weren’t many secrets about our sex lives. We knew Gary had a big cock, ex even gave it a good feel once to find how true that was. Kat loved that about him but hated that he wouldn’t lick her pussy or if he did it wasn’t for very long. They knew my ex and I had both had some bi experiences with my ex having had a couple of relationships with girls before we were married.
The girls would often catch of for coffees etc and it was one day after this then my ex came home and told me about their chat. Kat was complaining about how much she missed having her pussy licked and how she’d tried many ways to get Gary to but failed. To my surprise my ex told me she’d offered Kat my services as a one off to help her out. Kat said she couldn’t cheat on her hubby but ex said if it helped she’d happily suck Gary’s cock just to make it even of course. We had a laugh and I agreed that if she ever changed her mind I’d happily help her out.
We continued to see them and hang out a lot with them but nothing was ever said or acted upon. The girls continued to make out when pissed. The highlight of which was one night at a party where the girls were so pissed they were laying on the floor making out with everyone gathering around to watch. My ex had lovely DD boobs and Kat had got one out and was sucking on it and my ex had slid her hand up Kats skirt and was playing with her pussy. Needless to say not long after we went home but not before my ex sucked my cock in the car in the car park.
Some months later we were having a party at our place and suggested Kat and Gary could stay in the guests bedroom as they usually used taxis to be able to drink.
Party was going well loads of food and drink. My ex was being a great hostess and looked so sexy in a red corset top and little black skirt. To be honest I just wanted to bend her over and fuck her. Kat also looked sexy in a light summer dress that highlighted her shapely sexy body.
At one point in the night my ex went missing so I went looking for her and found her outside tucked away making out with Gary. I stood quietly and watched for a bit knowing she really wanted to suck his big dick. I have them a few minutes before going out of sight and calling her and she came out and we did whatever it was I needed her for.
The night went on and Gary got so drunk Kat and I put him to bed and he passed out almost straight away. My ex still being the wonderful hostess. Kat then kept drinking obviously trying to catch up to her hubby. She got so drunk she needed to throw up so I took her to our ensuite as it was away from everyone and they didn’t all need to know how drunk she was. I tied her hair back and looked after her. My ex would come in every now and then to see how she was. It was the end of the night and most ppl had left. With a few helping my ex tidy up. Meanwhile Kat kept telling me how sorry she was and how amazing my ex and I were etc. etc. somehow she got onto that chat her and my ex had. Asking lots of questions which I answered as I was pretty sure she’d forget it all. Then she surprised me by pulling her dress up and showing me her beautiful waxed pussy and asked if I was her hubby would I lick it lots. I pulled her dress down and told her she was drunk and needed to rest. The cycle of her lifting her skirt and asking if I’d like to lick it and me pulling it back down and trying to change the subject went on at least half a dozen times. She’d stopped being sick so I decided it was time to get my ex to help me out her in bed with Gary. When I got out to the party and everyone was gone with no signs of ex either. I went outside assuming she was probably having a smoke. She wasn’t and I found her in the guest room. I could hear some noises in there so I quietly opened the door a little to she her with her back to me kneeling on the floor next to the bed sucking on Gary’s cock. This was the first time I’d seen it and it was very big probably 10” and quite thick. She was oblivious I was there watching. She was loving his cock taking her time using her tongue and mouth all over it. He was awake and aware of when she was doing but was only able to let out sounds of pleasure. I was stood rubbing my cock. But then I remembered Kat and went back to her. She was now asleep on the ensuite floor and I had no chance of moving her alone. So I grabbed a blanket to cover her until I could get help to move her.
I went back to the guest room to carefully keep watching. My ex was still on her knees eagerly sucking his cock but now she has her left hand under her skirt playing with her pussy. I backed away and quietly removed my pants before quietly opening the door. My ex turned her head to see me while still sucking his cock. I went over and grabbed her by the hips and picked her up. I parted her legs and flipped her skirt up to find she’d already removed her knickers. I put my hand down and found a very wet and ready pussy. I moved behind her and easily slid my cock into her and started to fuck her gently and slowly. She didn’t want this she stopped sucking his cock and turned to me demanding I fuck her hard and properly. She went straight back to sucking his cock clearly working hard for the cum reward she wanted from him. Soon enough he grabbed her head and held it as he blew his load in her mouth. This shocked me as she didn’t usually like that. Once he’d finished blowing and she cleaned him up we stopped to get dressed and to bring Kat into the bed with him.